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Medium-sized (4.0-8.0 mm), yellowish to dark brown midges. Head with
dichoptic eyes, without ocelli; antenna elongated with scape and
pedicel short, flagellum with 14 segments. Mouthparts
non-functional. Thorax hump-backed, mesonotum usually with dark
longitudinal stripes, coxae relatively short, legs long and narrow,
abdomen elongated and narrow. Wings hyaline, in species of Dixa
Meigen, 1818 with dark markings, wing membrane without macrotrichia
or scales. The larvae are aquatic, eucephalic, with several
distinctive features (crowns, combs, terminal complex) that are
widely used for the identification of species groups; they rest in a
characteristic U-shaped position at the water meniscus. The larvae
of Dixa prefer running waters, while those of Dixella
Dyar & Shannon, 1924 live in stagnant waters. The adults are poor
fliers and can be found near the larval habitat.
There are some 400 described species in the world (Wagner
1997,
2007) and about 30 species in Europe (Wagner
2007). Altogether 12 species are listed in the present checklist – 11 from the Czech Republic
(10 in Bohemia, 11 in Moravia), and 10
from Slovakia. Since the PCV2 (Knoz
1997), no species have been added to the Czech Republic, but three
species have been added for Bohemia and one for Moravia; and five species
have been added to the fauna of Slovakia (Bitušík
1995,
Bulánková & Halgoš 1999,
Halgoš & Bulánková 2003,
Martinovský 1998,
Martinovský
& Barták 2000,
Ševčík 2006).
Since the ECV1 (Ševčík
& Halgoš 2006),
one aditional species was recorded as new to the Czech republic
(Ševčík
2007)
and one as new for Bohemia (Ševčík
et al. 2009).
The species composition of the Dixidae in both the Czech Republic and
Slovakia is still inadequately known, because no specific faunistic research
has yet been carried out. Most of the records from Slovakia should be
verified, because they are based only on the identification of the larvae.
The basic characteristics of the family were recently given by
Disney (1999) and Wagner
(1997), including keys to both the larvae and adults of
most European species. The nomenclature in the present checklist
follows that in the Fauna Europaea (Wagner
2007).
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